In development and production of semiconductor devices, testing costs may be 50% of the total manufacturing costs. Relatively high testing costs may be attributed to the gradual switchover to NANO processes and relatively fast development of various system LSI technologies. Some testing may verify if a manufactured chip operates, which may improve reliability and yield. Testing may be an important aspect of minimizing manufacturing costs.
CMOS image sensors (CIS), which may be implemented in IT information industry, may be used to generate and/or transmit picture images in digital cameras, cellular phones, or other devices. Manufacturers in the semiconductor area may need CIS test technologies to perform failure analysis and improve yield.
A CMOS image sensor is an image sensor, which may include an integrated circuit having hundreds of thousands to millions of embedded pixels. Each pixel may function to convert light-energy into an electrical signal. Visible original images (e.g. people or objects) may be converted into output electrical signals. An apparatus which may test electrical and optical properties of image sensors may require a separate illuminator to supply light, which may be different to a testing apparatus used to test other types of semiconductor devices.
In order to test electrical and optical signals of an image sensor in the form of a chip, a special digital signal processing (DSP) device and a programming technology (which may control the DSP device in a precision and efficient manner) may be needed. A semiconductor device tester may include a substrate equipped with multiple drive circuits (which may supply various test signals). Multiple connectors may be mounted on a substrate, which may connect to semiconductor device (e.g. an image sensor). A semiconductor device may be electrically connected with a connector and may be supplied with various test signals from drive circuits mounted on a substrate.
To test a semiconductor device in a wafer, a substrate may include multiple probe pins. Probe pins may come in close contact with the surface of a wafer and may supply test signals to the wafer. Test equipment may inspect a wafer on a die basis. Different semiconductor devices may have different shapes and sizes. Different test substrates may have to be used for different semiconductor devices, which may not allow for the minimization of costs.